VEHICLE MOUNTED CLOCK

PURPOSE:To correct a time very accurately and to omit cumbersome correcting operation by providing a constitution wherein the time is corrected automatically based on the time data from a GPS satellite provided with an atomic clock. CONSTITUTION:A radiowave which is received with a GPS receiver 1 is inputted into a CCS 3 having the navigation function of a vehicle and a control unit 4 for correcting the time of a vehicle-mounted clock through an adapter 2, respectively. Whether the time data are received or not is judged. When the data are received, the counted value of a counting part 7 which is driven with a counter driving part 6 is compared with the received time data, and whether the values agree or not is judged. When the values disagree, a correcting signal is generated, and the specified counted value is corrected based on the command. Since the time of a clock 5 is automatically corrected, the accuracy on the level of the atomic clock is secured.